Of course they were: Bernie wasn't a Democrat until he ran for the nomination, why would they want to help an outsider become head of the party (aka the nominee?)
And it's not like we don't have an example of a candidate that rode popular outrage to a comfortable nomination victory with the entire weight of the party elites trying to sink him. It's clearly not that hard if you find the right message and the time is right.
But then nobody hacked the RNC's emails. Who knows what's in those.